I had a harness made by Tweak'd Performance for my Beams Redtop into a 1990 Celica GT-S. The harness was literally plug and play and also looked and fit like an original Toyota harness. I considered the price reasonable at $550 (shipping included) but I've heard that you might get a better price for the same quality from a user named MR220V on http://www.mr2.com/forums/forum.php

The quality looks fantastic. That's one reason I was considering them. I didn't know anyone else did wiring like that. Thanks for the tip. Ill be sure to check mr220v out for a quality/price comparison. Fussell, did you send in the two harness' to be spliced in, or was it all brand new?

I've had a harness done by them but honestly id go somewhere else if I want able to do it my self. I took apart my harness 6months after getting it done because the car ran like shit and if you moved the harness it would run right again. I fount the crank sensor wire had a razor blade cut in it. Mind you I used dikes to get the harness apart. The shielding was touching the crank wires.

I'm not bashing them but I wouldn't go that route again. I would just do it myself if I do another swap.

GT-Steezy wrote:The quality looks fantastic. That's one reason I was considering them. I didn't know anyone else did wiring like that. Thanks for the tip. Ill be sure to check mr220v out for a quality/price comparison. Fussell, did you send in the two harness' to be spliced in, or was it all brand new?

I sent my harness from the car and the one that came with my engine. I haven't run the car much since the engine swap so I can't comment on durability yet.

Is wiring the harness a reasonable feat with enough research. I've done my fair share of car audio, but that probably doesn't begin to compare. Someone around my area used to be into celicas and motor swaps, don't know if he's even around anymore. But I do have a shop with the required tools I could get some time at. Is there a thread on wiring I overlooked? Thanks for the input!

It's not too bad iv had my harness apart a few times. Basically your taking your harness that came with your car and adding the the new stuff from the new harness. There's pins outs available for the 3s engines all over. If you buy the toyota oem wire diagram book it's pretty easy.

It would be fairly easy to do if you had the correct pinouts, I am a controls electrician, I fabricate electrical panels for machinery and I did my little brothers harness, it was probably the hardest thing I have ever wired, but we were going from a usdm to a jdmrc motor. It was easy to find the us wiring diagrams, but getting everything for the jdm harness was tough, I had to goin gt4oc.com to get all of the diagrams I needed, but once you have those, document everything (label) from each harness and take measurments from your stock harness, off of reference points like were there is a "Y" in the harness. That way everything will go back to the way it was, and if you want that cool wire loom those companies use you can get it at grainger or sonicelectronix.com or any place like that and it is fairly cheap. All I can say is document, document, document, and only solder or run completely new wires all the way to the ecu if you can.

anothergt4 wrote:All I can say is document, document, document, and only solder or run completely new wires all the way to the ecu if you can.

That's the secret right there. Label everything you cut on both sides of the cut with tape AND mark it down on a separate piece of paper or on the computer. Don't cut or move anything until you have documented how it was originally.

As for the professional wiring guys - if you have somebody else do the work, you'll still want to check it over for quality before installing. It would be better to get the harness back un-loomed so you can look over the whole thing yourself.

Tweak has a really good reputation. Check out the feedback forums on mr2oc.com. That said, I used mr220v for my Caldina swap and it's been running great for a couple years, plus he provided support to my installer during the swap. His quote was also lower than that I got from Tweak.

I'd get a quote and check out the feedback from both and make your decision from there.